Cortical oscillopsia without nystagmus, an isolated symptom of neuromyelitis optica spectrum disorder with anti-aquaporin 4 antibody

Neuromyelitis optica spectrum disorder: Exploring the diverse clinical manifestations and the need for further exploration

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune disorder characterized by inflammatory assaults on the central nervous system (CNS), particularly on the optic nerves and spinal cord. In recent years, a wider range of clinical manifestations of this complex disease have been observed, emphasizing the importance of gaining a more profound understanding beyond optic neuritis (ON) and transverse myelitis (TM).

CURRENT KNOWLEDGE

This study explores the many clinical symptoms of NMOSD, including common and uncommon presentations. Distinctive aspects of ON, TM, and diencephalic/brainstem syndromes are examined, highlighting their unique characteristics in contrast to conditions such as multiple sclerosis. We also discuss extra-CNS involvement, such as unusual signs, including muscle involvement, retinal injury, auditory impairment, and rhinological symptoms.

AIMS AND OBJECTIVES

Our study intends to highlight the wide range and complexity of NMOSD presentations, emphasizing the significance of identifying unusual symptoms for precise diagnosis and prompt management. The specific processes that contribute to the varied clinical presentation of NMOSD are not well understood despite existing information. This emphasizes the necessity for more study to clarify the mechanisms that cause different symptoms and discover new treatment targets for this complex autoimmune disorder.

CONCLUSION

It is essential to acknowledge the complex and varied clinical manifestations of NMOSD to enhance diagnosis, treatment, and patient results. By enhancing our comprehension of the fundamental processes and investigating innovative therapeutic approaches, we may aim to enhance the quality of life for persons impacted by this illness.

Neuromyelitis Optica Spectrum Disorder Complicated by Posterior Reversible Encephalopathy Syndrome as an Initial Manifestation

A 25-year-old woman was admitted to our hospital due to tonic convulsion with severe headache after having experienced symptoms of nausea and vomiting for a month. Brain magnetic resonance imaging showed extensive symmetrical lesions in the cortical and subcortical areas of parieto-occipital lobes and basal ganglia, consistent with typical characteristics of posterior reversible encephalopathy syndrome (PRES). Furthermore, some residual lesions in the left side of dorsal medulla oblongata and central area of the cervical spinal cord along with the presence of serum anti-aquaporin-4 antibody yielded the diagnosis of neuromyelitis optica spectrum disorder (NMOSD). We herein discuss the mechanism by which PRES may occur together with NMOSD.

Eye movement abnormalities in AQP4-IgG positive neuromyelitis optica spectrum disorder

BACKGROUND AND PURPOSE

Neuromyelitis optica spectrum disorder (NMOSD) has been recognized as a disease characterized by severe visual afferent impairment. Abnormal eye movements, as the other important neuro-ophthalmic manifestation of NMOSD, were commonly overlooked. The aim of our study was to describe the ocular motor manifestations of AQP4-IgG positive NMOSD patients, and explore the value of eye movement abnormalities in the evaluation of the disabled disease.

METHODS

Systemic clinical bedside ocular motor examinations and quantitative horizontal saccadic eye movement assessments were performed in 90 patients with AQP4-IgG positive NMOSD. General disability was evaluated by expanded disability status scale (EDSS). Vision-specific functional status was evaluated by the National Eye Institute-Visual Function Questionnaire (NEI-VFQ 25) and the 10-item neuro-ophthalmic supplement. Brain magnetic resonance imaging (MRI) was acquired in all patients.

RESULTS

In clinical examination, eye movement abnormalities were found in 38% of NMOSD patients. Abnormalities in the quantitative saccadic test were found in 67% of NMOSD patients, including 48% of patients with clinically normal eye movements. EDSS scores in patients with clinical eye movement abnormality were significantly higher (P<0.001) than those with a normal examination. The 10-item neuro-ophthalmic supplement score was significantly associated with quantitative saccadic eye movement abnormalities (P=0.031).

CONCLUSIONS

Eye movement abnormalities were common in AQP4-IgG positive NMOSD patients, and were associated with general disability and specific visual handicap. The systemic clinical eye movement examination combined with the quantitative saccade test was easy to perform, and could provide additional useful information in evaluating NMOSD.

Differential diagnosis of neuromyelitis optica spectrum disorders

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory disorder of the central nervous system (CNS) mostly manifesting as optic neuritis and/or myelitis, which are frequently recurrent/bilateral or longitudinally extensive, respectively. As the autoantibody to aquaporin-4 (AQP4-Ab) can mediate the pathogenesis of NMOSD, testing for the AQP4-Ab in serum of patients can play a crucial role in diagnosing NMOSD. Nevertheless, the differential diagnosis of NMOSD in clinical practice is often challenging despite the phenotypical and serological characteristics of the disease because: (1) diverse diseases with autoimmune, vascular, infectious, or neoplastic etiologies can mimic these phenotypes of NMOSD; (2) patients with NMOSD may only have limited clinical manifestations, especially in their early disease stages; (3) test results for AQP4-Ab can be affected by several factors such as assay methods, serologic status, disease stages, or types of treatment; (4) some patients with NMOSD do not have AQP4-Ab; and (5) test results for the AQP4-Ab may not be readily available for the acute management of patients. Despite some similarity in their phenotypes, these NMOSD and NMOSD-mimics are distinct from each other in their pathogenesis, prognosis, and most importantly treatment. Understanding the detailed clinical, serological, radiological, and prognostic differences of these diseases will improve the proper management as well as diagnosis of patients.

Cerebral Cortex Involvement in Neuromyelitis Optica Spectrum Disorder

BACKGROUND AND PURPOSE

Brain lesions involving the cerebral cortex are rarely described in patients with neuromyelitis optica spectrum disorder (NMOSD), in contrast to multiple sclerosis. We investigated cerebral cortex involvement using conventional brain magnetic resonance imaging (MRI) in anti-aquaporin-4 (AQP4)-antibody-positive NMOSD patients.

METHODS

The study enrolled 215 NMOSD patients who were seropositive for the anti-AQP4 antibody from 5 referral hospitals, and retrospectively analyzed their demographic, clinical, and MRI findings. Abnormal cerebral cortex lesions on brain MRI were identified by a neuroradiologist and two neurologists using consensus.

RESULTS

Most of the 215 enrolled patients (87%) were female. The median age at onset was 22.5 years (range: 15-36 years) and the mean follow-up duration was 123 months. Brain lesions were found in 143 of 194 patients (74%) in whom MRI was performed during follow-up. Brain lesions involving the cerebral cortex were identified in 6 of these 194 patients (3.1%). Five of the patients were female, and the six patients together had a median age of 29 years (range: 15-36 years) at the time of lesion presentation. Three of them showed leptomeningeal enhancement in the lesions. At presentation of the cortex-involving lesions, five of these patients were not being treated at the time of presentation, while the sixth was being treated with interferon-beta.

CONCLUSIONS

Although rare, cortical involvement occurs in NMOSD and is commonly combined with leptomeningeal enhancement. We speculate that this occurs only in patients who are not treated appropriately with immunosuppressant drugs.

Neuromyelitis optica: clinical features, immunopathogenesis and treatment

The term 'neuromyelitis optica' ('Devic's syndrome', NMO) refers to a syndrome characterized by optic neuritis and myelitis. In recent years, the condition has raised enormous interest among scientists and clinical neurologists, fuelled by the detection of a specific serum immunoglobulin (Ig)G reactivity (NMO-IgG) in up to 80% of patients with NMO. These autoantibodies were later shown to target aquaporin-4 (AQP4), the most abundant water channel in the central nervous system (CNS). Here we give an up-to-date overview of the clinical and paraclinical features, immunopathogenesis and treatment of NMO. We discuss the widening clinical spectrum of AQP4-related autoimmunity, the role of magnetic resonance imaging (MRI) and new diagnostic means such as optical coherence tomography in the diagnosis of NMO, the role of NMO-IgG, T cells and granulocytes in the pathophysiology of NMO, and outline prospects for new and emerging therapies for this rare, but often devastating condition.

Brain abnormalities in neuromyelitis optica spectrum disorder

Neuromyelitis optica (NMO) is an idiopathic inflammatory syndrome of the central nervous system that is characterized by severe attacks of optic neuritis (ON) and myelitis. Until recently, NMO was considered a disease without brain involvement. However, since the discovery of NMO-IgG/antiaqaporin-4 antibody, the concept of NMO was broadened to NMO spectrum disorder (NMOSD), and brain lesions are commonly recognized. Furthermore, some patients present with brain symptoms as their first manifestation and develop recurrent brain symptoms without ON or myelitis. Brain lesions with characteristic locations and configurations can be helpful in the diagnosis of NMOSD. Due to the growing recognition of brain abnormalities in NMOSD, these have been included in the NMO and NMOSD diagnostic criteria or guidelines. Recent technical developments such as diffusion tensor imaging, MR spectroscopy, and voxel-based morphometry reveal new findings related to brain abnormalities in NMOSD that were not identified using conventional MRI. This paper focuses on the incidence and characteristics of the brain lesions found in NMOSD and the symptoms that they cause. Recent studies using advanced imaging techniques are also introduced.

Neuromyelitis optica

Neuromyelitis optica (NMO) is a disabling inflammatory condition that targets astrocytes in the optic nerves and spinal cord. Neuro-ophthalmologists must be particularly aware of this disorder because about half of patients present as isolated unilateral optic neuritis months or years before a disease-defining and often crippling bout of myelitis. NMO is easily confused with multiple sclerosis because it is characterized by relapses that lead to stepwise accrual of deficits. The best predictor of conversion from optic neuritis to clinical definite NMO is the presence of a serum antibody to aquaporin-4 called NMO-IgG. However, this test is currently only about 75% sensitive. Suspicion of NMO should be high in patients who present with vision of light perception or worse or who are left with acuity of 20/50 or worse after optic neuritis and in those with simultaneous bilateral optic neuritis or recurrent attacks. Acute NMO relapses are generally treated with high-dose intravenous steroids, with plasma exchange often used as a rescue therapy for those who do not respond. Preventative strategies against relapses currently use broad-spectrum or selective B-lymphocyte immune suppression, but their use is based on small, generally uncontrolled studies. Hopefully, the future will bring more sensitive tools for defining risk and predicting outcome, as well as more targeted and effective forms of therapy.